Performance of the Khon Kaen Osteoporosis Study (KKOS) Score for Identifying Osteoporosis in Men
Chatlert Pongchaiyakul MD*, Ekgaluck Wanothayaroj MD*
Affiliation : * Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Khon Kaen University, Khon Kaen
Objective : The present study evaluated the diagnostic performance of Khon Kaen Osteoporosis Study (KKOS)
score in identifying osteoporosis in men.
Materials and Methods : This was a cross-sectional investigation in 230 men aged > 50 years. Bone mineral
density (BMD) was measured at the femoral neck and lumbar spine by DXA (DPX-IQ densitometer, LUNAR
Corporation, Madison, Wisconsin, USA). The KKOS score was calculated for each man using his age and
weight. Men with KKOS scores < -1 and > -1 were classified as “high risk” and “low risk”, respectively.
Results : The prevalence of osteoporosis in the entire sample was 17% and 7.4% (n = 39, 17) by femoral neck
BMD and lumbar spine BMD, respectively. Using the KKOS score, 80 (34.8%) men were classified as “high
risk” (KKOS score < -1). The proportion of high risk individuals increased with advancing age, ranging from
16.2% in the 50-65 age group to 64.8% in the > 65 age group. Using BMD from DXA as a gold standard, the
overall sensitivity and specificity of KKOS in identifying osteoporosis was 72.5% and 73.2%, respectively.
However, the sensitivity was higher at the lumbar spine (94.1% vs. 71.8%) than the femoral neck, while the
specificity was comparable. The PPV of KKOS was 36%; and was lower at the lumbar spine (20%) compared
to the femoral neck (35%). In the present study, men were classified “high risk” from KKOS, the risk (odds
ratio; OR) of osteoporosis at the femoral neck and/or lumbar spine was 7.19 (95%CI: 3.34-15.44). However,
the risk of osteoporosis was higher in the younger age (50-65 yr) group (OR: 10.29, 95%CI: 3.31-31.94)
compared with the older age (> 65 yr) group (OR: 3.65, 95%CI: 1.12-11.91).
Conclusion : KKOS scoring system based on age and body weight, is a simple tool for clinicians to make a
decision to further DXA testing for identifying osteoporosis in Thai men. This tool had a high sensitivity and
specificity, but modest PPV.
Keywords : Clinical risk index, Epidemiology, Men, Osteoporosis, Thailand
